Wednesday, April 27, 2016

I'm chronicling my adventures in the lab to bring what it's like to work as a new scientist to the forefront.

On pipettes

You are given a long pointy instrument that measures to the precision of microliters. You are told to transfer tiny rain droplets of what looks like spit. Your hands have the tendency to shake. The gloves on your hands feel weird like there is less hold or contact.

The naïve biotech wannabe must first face the task of learning to pipette. In brief, a pipette is a glorified turkey baster. During the course of a lab day, one has to choose between a p10, p20, p200, and p1000. The numbers signify the largest amount of microliters that pipette can handle. I don't know what the "p" stands for. Probably, pipette.

Pipettes are good at sucking and spitting out. I know that's not flattering, but it will be your constant companion.

So, you have to treat it right, but that can be a challenge. There's a lot to mess up like:

Touching the tip of the pipette to any surface in the lab- That's how you get contamination in your samples.

Holding the pipette horizontally- Keep the pipette tip pointed down. Gravity rules all. Your pipetted material will flow up into the pipette. Then, it will be dirty the next time someone else uses it. I'm no clean freak. I don't take messiness seriously, except for in the lab. In that environment, being a little unsanitary could mean a project delay of months and wasted money (thousands). What if someone's working on a cure for HIV and you delay that? Sad. It could also cause a biohazard.

Get a clean pipette tip every time you pipette into a new container. Don't double dip.

When ejecting a pipette tip, (you push a fancy ejection button) don't put it inside the ejection container. Keep it a few inches above. It's cleaner that way.

Basic Use: MEASURE, STAB, SUCTION, EXPULSION

Slide a rotating knob to measure your amount in microliters.

Stab pipette into a matching sized tip.

Press plunger down, and stop when you first meet resistance.

Place in the sample and remove thumb pressure from the plunger.

Release your sample by pressing the plunger down once again to the second click.

Getting used to the feeling of when you're pipetting to the first or second click sometimes takes time. You need it for accuracy, though.

Quick tips:

Practice pipetting droplets of water on wax paper until you get a feel for the instrument.

Pipette your cheap liquids first. It is ideal to start with something like water and to destroy a water only sample than to start with an expensive enzyme and mess that sample up.

If the material you are working with is viscous, dip the pipette tip only near the surface. This prevents extra material from sticking to the outside of the pipette.

Try to place the sample you are transferring into the bottom of the tube.

Avoid blowing bubbles.

Shaking hands can get better with increased comfort and the loss of newbie's nerves . You can stabilize your arms further by putting both elbows on a table and holding your wrist with your nonpipetting hand.

Always think a second ahead about what container you need to open just before you pipette up liquid. Close containers shortly after to minimize contamination.